The embodiments of the present invention relate to active vehicle suspension systems incorporating continuously variable or multistep suspension dampers, and to methods for controlling such systems.
Vehicles may incorporate active or adaptive suspension systems to actively control the vertical movements of the vehicle wheels rather than allowing such movements to be determined entirely by interactions with the road surface. In order to maximize ride comfort in such vehicles, it is usually desirable to maintain the damping levels in vehicle shock absorbers at a relatively low value.
However, when a vehicle wheel encounters a depression (such as a pothole) in the road surface, a lower damping level permits the wheel to fall relatively rapidly into the pothole. Generally, the deeper the wheel falls into the hole, the greater the impact forces generated by the wheel impacting a far side of the hole just prior to rising out of the hole. With the wheel damping level at a relatively low value, these impact forces are transmitted through the vehicle suspension to the remainder of the vehicle, adversely affecting ride quality.
While increasing the level of wheel damping would reduce the impact forces transmitted to the vehicle and suspension, this would adversely affect ride quality when the vehicle is traveling on a normal, level road surface. Thus, it is desirable to increase damping levels only when a pothole is encountered, while maintaining the damping levels at the relatively lower value when the wheel is riding on a level road surface.